Effect of Trichoderma viride T1433 on the pectolytic enzyme activity of Rhizopus stolonifer (= R. artocarpi) during the development of soft rot of jackfruit was studied. Activity of different fractions of pectolytic enzymes like PG, PME and PL was investigated during pathogenesis and correspondingly the associated resistance of the host was assayed. It was noticed that the biocontrol agent, Trichoderma significantly interacts with the pectolytic enzyme activity of the pathogen. It caused an appreciable reduction in enzymatic action. The reduction in the activity of polygalacturonase enzyme (PG) was recorded to be the highest among all the fractions of pectolytic enzymes. Such a trend appeared to be more pronounced in 'Kujja' than in 'Ghula' cultivar of jackfruit. The reduction in pectolytic enzyme activity was found to be coupled with a significant increase in the activity of polyphenol oxidase enzyme of the host tissues and a concomitant increase in host phenol content. Such inter-relationship between these two enzyme systems plays a key role to stimulate the defense mechanism of the host plant against infection. Significant increase in total phenol content of the host tissue during Trichoderma plant pathogen interaction that was recorded may correspond with the host defense response.
The growth and morphology of filamentous fungusTrichoderma viride grown in the presence of various Co concentrations were studied. Using60Co, the cobalt content in mycelium and conidia was determined. No influence of60Co-radiation on growth and morphology was observed.
Authors:E. PAYGHAMI, S. MASSIHA, B. AHARY, M. VALIZADEH, and A. MOTALLEBI
The effect of Trichoderma harzianum and Trichoderma viride (isolated from mycoflora in the rhizosphere of onion) in increasing the growth of onion was studied in a completely randomized design in pots with 12 replications under greenhouse conditions at 21°C with a 12-h light/dark cycle (fluorescent and incandescent lighting). The biological control of Sclerotium cepivorum Berk, the causal agent of white rot of onion, was also investigated in this experiment. The addition of Trichoderma spp. to autoclaved soil (inoculation of 2/3 of the top soil in the pots with 4% (v/v) inoculum of T. harzianum and T. viride) significantly increased the growth and fresh weight of the onion plants (P=1%). The biological control of S. cepivorum was achieved with T. harzianum and T. viride, but no significant difference was observed between the two species.
Authors:L. Rajendran, R. Akila, G. Karthikeyan, T. Raguchander, and R. Samiyappan
. Univ. , Coimbatore .
Ramakrishnan , G. , Jeyarajan , R. and Dinakaran , D. ( 1994 ): Talc based formulation of Trichodermaviride for biocontrol of Macrophomina phaseolina . J. Biol. Control 8 , 41 – 44 .
Rangasamy , R. ( 1995